<template>
  <div style="display:inline-block;">
    <input ref="excel-upload-input" class="excel-upload-input" type="file" accept=".xlsx, .xls" @change="handleClick">
    <el-button type="primary" @click="handleUpload" size="mini" :loading='loadingstatus'>
      选择导入文件
    </el-button>  
  </div>
</template>

<script>
import XLSX from 'xlsx'

export default {
    props: {
        beforeUpload: Function, // eslint-disable-line
        onSuccess: Function,// eslint-disable-line
        loadingstatus: { type: Boolean, default: false }
    },
    data() {
        return {
            loading: false,
            excelData: {
                header: null,
                results: null
            }
        }
    },
    methods: {
        generateData({ header, results }) {
            this.excelData.header = header
            this.excelData.results = results
            this.onSuccess && this.onSuccess(this.excelData)
        },
        handleDrop(e) {
            e.stopPropagation()
            e.preventDefault()
            if (this.loading) return
            const files = e.dataTransfer.files
            if (files.length !== 1) {
                this.$message.error('Only support uploading one file!')
                return
            }
            const rawFile = files[0] // only use files[0]

            if (!this.isExcel(rawFile)) {
                this.$message.error('Only supports upload .xlsx, .xls, .csv suffix files')
                return false
            }
            this.upload(rawFile)
            e.stopPropagation()
            e.preventDefault()
        },
        handleDragover(e) {
            e.stopPropagation()
            e.preventDefault()
            e.dataTransfer.dropEffect = 'copy'
        },
        handleUpload() {
            this.$refs['excel-upload-input'].click()
        },
        handleClick(e) {
            const files = e.target.files
            const rawFile = files[0] // only use files[0]
            if (!rawFile) return
            this.upload(rawFile)
        },
        upload(rawFile) {
            this.$refs['excel-upload-input'].value = null // fix can't select the same excel
            console.log(rawFile)
            if (!this.beforeUpload) {
                this.readerData(rawFile)
                return
            }
            const before = this.beforeUpload(rawFile)
            if (before) {
                this.readerData(rawFile)
            }
        },
        readerData(rawFile) {
            this.loading = true
            // return new Promise((resolve, reject) => {
            return new Promise((resolve) => {
                const reader = new FileReader()
                reader.onload = e => {
                    const data = e.target.result
                    const workbook = XLSX.read(data, { type: 'array' })
                    const firstSheetName = workbook.SheetNames[0]
                    const worksheet = workbook.Sheets[firstSheetName]
                    const header = this.getHeaderRow(worksheet)

                    const range = XLSX.utils.decode_range(worksheet['!ref']);
                    // 获取表头（第一行）
                    const headers = [];
                    for (let col = range.s.c; col <= range.e.c; col++) {
                        const cellAddress = XLSX.utils.encode_cell({ r: 0, c: col });
                        const cell = worksheet[cellAddress];
                        headers.push(cell ? String(cell.v) : "");
                    }

                    const results = []
                    for (let row = 1; row <= range.e.r; row++) {
                        const rowData = {};
                        for (let col = range.s.c; col <= range.e.c; col++) {
                            const _cellAddress = XLSX.utils.encode_cell({ r: row, c: col });
                            const cell = worksheet[_cellAddress];
                            const _header = headers[col] || `Column ${col + 1}`; // 确保有标题，即使为空
                            if (cell) {
                                // 确保布尔值被转换为字符串
                                if (typeof cell.v === 'boolean') {
                                    rowData[_header] = cell.v ? 'TRUE' : 'FALSE';
                                } else {
                                    rowData[_header] = String(cell.v);
                                }
                            } else {
                                rowData[_header] = ""; // 处理空单元格
                            }
                        }
                        results.push(rowData);
                    }

                    this.generateData({ header, results })
                    this.loading = false
                    resolve()
                }

                reader.readAsArrayBuffer(rawFile)
            })
        },
        getHeaderRow(sheet) {
            const headers = []
            const range = XLSX.utils.decode_range(sheet['!ref'])
            let C
            const R = range.s.r
            /* start in the first row */
            for (C = range.s.c; C <= range.e.c; ++C) { /* walk every column in the range */
                const cell = sheet[XLSX.utils.encode_cell({ c: C, r: R })]
                /* find the cell in the first row */
                let hdr = 'UNKNOWN ' + C // <-- replace with your desired default
                if (cell && cell.t) hdr = XLSX.utils.format_cell(cell)
                headers.push(hdr)
            }
            return headers
        },
        isExcel(file) {
            return /\.(xlsx|xls|csv)$/.test(file.name)
        }
    }
}
</script>

<style scoped>
.excel-upload-input{
  display: none;
  z-index: -9999;
}
.drop{
  border: 2px dashed #bbb;
  width: 600px;
  height: 160px;
  line-height: 160px;
  margin: 0 auto;
  font-size: 24px;
  border-radius: 5px;
  text-align: center;
  color: #bbb;
  position: relative;
}
</style>
